:salamext:
I think linguistically tadlees means 'hiding the defect of a product from the purchaser'. But in mustalah it's basically when you try to improve the appearance of the hadeeth’s isnaad. There are
three types:
Tadlees at-Tajweed/at-Tasweeyah: This is where a later narrator of a hadeeth fails to mention the name of a weak narrator who comes between two reliable narrators, who have both met each other (so there is a chance that they could have reported from each other), which gives the appearance that the chain of narrators are all thiqqah. While in fact, the thiqqah reporter heard it from a weak reporter. So in this way, the chain would be considered Da’eef.
The word 'an is often used between the two reliable narrators, which is similar to 'he quoted".
Tadlees al-Isnaad: This is where the narrator quotes from someone something that he had heard from him indirectly, but uses ambiguous language (like 'an) to hide the fact that he actually heard it indirectly. He might simply say things like: “So and so said…”
Just quickly searching, I found out that there are a number of definitions given by earlier scholars:
--The narrator reports from his teacher [whom he has heard some hadeeth from]
other hadeeth which he has not heard directly from his teacher;
but he has actually heard it through a third party –
and he uses an expression (such as Qaala: he said or ‘An: from)
which gives the impression – without actually saying it –
that he has heard it directly from his teacher.
--The narrator reports from a contemporary scholar [whom he may or may not have met]
Hadeeth which he did not hear from him,
Using an expression (such as Qaala: he said or ‘An: from so-and- so)
Giving the impression – without actually saying it –
That he has actually heard it directly from that contemporary scholar.
[Some scholars view this second definition as al-Mursal al-Khafee]
Tadlees al-shuyookh: This is where the narrator refers to his shaykh (or the person who he heard the hadeeth from) by a name,kunyah, title other than the one the sheikh is commonly known by, e.g. 'Abu Fulaan', yet no one knew him by that kunyah.
Do you want me to give you a real example, or make one up?
) hehe.